DISTRICT 8, SPRINGFIELD - Rumble strips designed to alert drivers to a stop sign ahead have been installed on Greene County Route EE at Route AB between Willard and Elwood, the Missouri Department of Transportation said.
The concrete slabs with recessed grooves running across the lane generate a low-frequency vibration, or rumble, when a vehicle's tires roll over them. This is designed to alert drivers to a condition up ahead that will require slowing down and stopping.
MoDOT has placed rumble strips at a number of intersections around the state to analyze whether they will help reduce traffic crashes, whether they will be effective in asphalt and/or concrete and how they will function in rain, snow and ice.
Route EE and AB was chosen as a test site for rumble strips because the stop signs on Route EE are relatively new. The stop signs on Route EE were installed in August 2003 because of an increase in right-angle crashes at the intersection.
The Route EE/AB intersection is located in an area where traffic is increasing as areas west and north of Springfield experience growth. Yet the area around the intersection remains relatively undeveloped and a stop sign may be unexpected.
MoDOT crews installed two sets of rumble strips on Route EE -- one set 625 feet away from the stop sign at Route AB and another set 300 feet back.
The evaluation is expected to take two to three years. MoDOT traffic engineers will monitor traffic crash statistics, based on accidents reported through law enforcement agencies, before and after installation of the stop signs and rumble strips on Route EE. The intersection also will be compared with the statewide accident average for intersecting roads of this type.
If rumble strips prove to be effective at the test intersections, MoDOT will develop guidelines for appropriate use statewide. MoDOT wants to avoid overuse of rumble strips, concerned that they will be too commonplace and drivers will stop paying attention to them.
Stop signs themselves are highly visible and are the only highway sign in the shape of an octagon.
However, in some locations, including Route EE at Route AB, MoDOT places signs back from an intersection that warn of a stop sign ahead. When a stop sign is placed in a new location, red warning flags are attached to help draw the attention of drivers.
Rumble strips are used on the shoulders of some highways to warn drivers when their cars begin to vere off the road.
